▲ Human lifespan evidence: no healthy-aging lifespan RCT — human evidence is a randomized, placebo-controlled telomere length biomarker RCT (Salvador 2016) plus an immune biomarker study; telomere length is a contested biomarker and the trials carry a commercial conflict of interest

Two caveats govern every page on this site. (1) Telomere length is a contested aging biomarker — it is measured differently by different methods, varies between tissues, and "longer" is not straightforwardly "healthier"; changing a telomere-length or telomerase-activity number in a trial is not the same as slowing human aging. (2) Activating telomerase is not risk-free — telomerase is silenced in most somatic cells and reactivated in most cancers, so its activation raises an unresolved cancer-risk question. Tellingly, the only FDA-approved telomerase drug — imetelstat (RYTELO, 2024) — inhibits telomerase to treat cancer (lower-risk MDS), the opposite direction from the anti-aging "activation" narrative.

What it is

Class: Astragalus-derived telomerase activator (supplement)

Also known as: TA-65, cycloastragenol, TA-65MD

Relationship to telomere biology: TA-65 is a small-molecule telomerase activator, an improved formulation of cycloastragenol purified from Astragalus membranaceus. It is the most-studied human 'telomerase activator' supplement; its randomized human data measure telomere LENGTH (a contested biomarker), not any clinical or lifespan outcome.

Regulatory status

Sold as a dietary supplement by T.A. Sciences; not an approved drug and not approved for any anti-aging, longevity, or healthspan indication. Supplement status is a marketing pathway, NOT evidence of an aging benefit.

Commercial conflict-of-interest note. The pivotal TA-65 human data — the telomere-length RCT (Salvador 2016) and the earlier immune study (Harley 2011) — were authored by people with a direct commercial interest in the product. TA-65 is sold by T.A. Sciences; Calvin Harley (a TA-65 co-inventor/commercial proponent) and other T.A. Sciences–affiliated authors appear on those papers. This does not automatically invalidate the results, but it is a material conflict of interest for a supplement marketed on telomere claims. TeloiX has no relationship with T.A. Sciences.

Mechanism

Reported to modestly activate telomerase (TERT) and, in a 1-year RCT, to increase measured telomere length in the low-dose arm. Telomere length is a contested biomarker and activating telomerase raises a cancer-risk question. See /telomerase-tert-terc, /telomere-length-biomarker, and /telomerase-cancer-paradox.

Evidence — Human (randomized, placebo-controlled — biomarker)

Species / population	117 relatively healthy CMV-positive adults aged 53–87 (Salvador 2016); an earlier immune-focused study of older adults (Harley 2011).
Exposure, route, schedule	Oral TA-65 (low dose 250 U/day; high dose 1000 U/day) over 12 months in the RCT.
Comparator / duration	Placebo-controlled, double-blind, randomized; 1-year duration.
Endpoint / numeric result	Low-dose TA-65 increased median telomere length by ~530 bp over 12 months (p=0.005) while placebo lost ~290 bp (p=0.01); the high-dose arm showed a non-significant trend. Harley 2011 reported a decline in senescent (CD8+CD28−) T cells.
What it did NOT establish	Both endpoints are contested biomarkers (telomere length; immune-cell subsets), not clinical outcomes. No healthy-aging, disease-outcome, or lifespan benefit is established, and the data carry a commercial conflict of interest.

Negative or null findings

The high-dose (1000 U) arm did NOT significantly increase telomere length in Salvador 2016 — the significant effect was low-dose only, an unusual dose-response for a supplement.
No clinical outcome, disease-outcome, or lifespan endpoint has been shown; a claimed 2025 meta-analysis is carried as unverified (needs_primary_fulltext).

TA-65 (cycloastragenol)

What it is

Regulatory status

Mechanism

Evidence — Human (randomized, placebo-controlled — biomarker)

Negative or null findings

Studies on this page

Related mechanisms